Hand-starting auxiliary device for internal combustion engines

ABSTRACT

An auxiliary device that is attached to the crankshaft of a hand-started internal combustion engine, comprising a beehiveshaped body having a base, adjacent to the engine, and a spiral groove therearound that terminates in a notch at the apex thereof within four full turns. The initial groove at the base comprises a double groove. Substantial inward progression of the groove toward the axis of the body approximately coincides with the initiation of firing by the engine, whereby high power input is sustained until firing commences, and rotational speed is increased thereafter.

United States Patent Perry 1 Feb. 13, 1973 [54] HAND-STARTING AUXILIARYDEVICE 1,622,289 3/1927 Nelson ..l23/185 A 2,286,419 6/1942 Krenzke.....123/185 BA ggg g g COMBUSTION 2;323,535 7/1943 Gorden ..123/185 BA2,530,623 11/1950 Martin ..123/185 BA Inventor: Donald R. Perry,Manderley Place,

Salem, W. Va. 26426 Filed: Nov. 10, 1971 Appl. No.: 197,393

Related US. Application Data Continuation-impart of Ser. No. 31,620,April 27, 1970, abandoned.

US. Cl. ..l23/185 A, 74/6 Int. Cl ..F02n 3/02 185 BA, 123/185 BB, 185 D,179 SE, 179 P; 74/6,506

References Cited UNITED STATES PATENTS v 6/1916 Davenport ..l23/l85 A UXPrimary ExaminerAl Lawrence Smith Att0rneyDonal E. McCarthy et a1.

[57] ABSTRACT An auxiliary device that is attached to the crankshaft ofa hand-started internal combustion engine, comprising a beehive-shapedbody having a base, adjacent to the engine, and a spiral groovetherearound that terminates in a notch at the apex thereof within fourfullturns. The initial groove at the base comprises a double groove.Substantial inward progression of the groove toward the axis of the bodyapproximately coincides with the initiation of firing by the engine,whereby high power input is sustained until firing commences, androtational speed is increased thereafter.

5 Claims, 4 Drawing Figures HAND-STARTING AUXILIARY DEVICE FOR INTERNALCOMBUSTION ENGINES This application is a continuation-in-part of myprior application Serial No. 31,620, filed April 27 1970, and nowabandoned.

BACKGROUND OF THE INVENTION 1. Field of the Invention This inventionrelates to devices for hand-started internal combustion engines whichare typicallyused for powering small tractors, cultivators, mowers,boats, snowmobiles, and the like, and particularly relates to devices,which are selectively attached to relatively small internal combustionengines for use with a pull rope in hand starting thereof.

2. Description of the Prior Art Such engines, whether two-stroke cycleor fourstroke cycle, require maximum sustained power input forovercoming resistance created by compression and friction of engineparts during initial phase of the starting process. A plurality ofrevolutions, generally two or three, are required before firing beginsand the engine is able to contribute its own power toward its rotation.It is at this point that the starting device should impart decreasedpower input and increased rotational velocity.

Devices in the prior art, such as US. Pat. No. 1,622,289 of Victor B.Nelson, have combined high initial powervinput with immediatelydecreasing power input and rapidly increasing rotational velocity. TheNelson device, designed nearly 50 years ago, was intended for a smallportable engine of the kind used for propelling canoes, rowboats and thelike when such engines were slow in rpm and low in brake horsepower sothat initial firing could occur earlier than in the relativelyhigh-compression, high speed, and high brakehorsepower engines of thepresent day when 100 H.P. outboard engines are becoming common on smallboats. For a frusto-conical Nelson body having a base diameter of 6.2inches as measured from center to center of the pull rope therealong,the cumulative circumference, C, of the spiral groove, as measured bythe length of wound pull rope thereupon, is given in inches in terms ofturns, T, through five full turns, as: C= 16.4 70.84

Specifically, when the bell-shaped Nelson body has made one completerevolution, the pull rope has moved so far inwardly toward the axis ofthe body that its leverage has significantly decreased, withcorresponding decrease in available power input to the engine. Becausefiring rarely begins within a single turn,

the loss in leverage seriously impairs the available power input beforefiring begins and also attempts to initiate relatively rapidrotationprematurely, particularly when. the device is used forattempting to start larger engines having relatively high brakehorsepower ratings and compression ratios. I

SUMMARY OF THE INVENTION It is an additional object of this invention toprovide means for attaching the accessory starting device of thisinvention to the crankshaft and over the pulley hub of an internalcombustion engine.

DESCRIPTION OF THE INVENTION The manual starting device for an internalcombustion engine of this invention comprises a beehiveshaped body whichis coaxially attached to the crankshaft of the engine and has a spiralgroove of sufficient width to accommodate a pull rope. This groove has adouble widthalong an initial portion of its length at the base of thebody and terminates in a pull notch at the apex thereof within four fullturns.

For a body having a base diameter of 6.2 inches as measured from centerto center of the pull rope therealong, the cumulative circumference, C,of the spiral groove, as measured by the length of wound pull Theinvention further comprises a means for simply and rapidly attaching thebeehive-shaped body onto the crankshaft of an engine. This attachingfeature comprises a central well which is open on the apex end of thebody and an annular slot that is open on the base side of the body,adjacent to the engine, the base of the well being substantially flushwith the base of the body and the sides of thewell forming the sides ofthe slot. A central opening in the base, and therefore also in the well,fits the crankshaft whereby there is coaxial fitting I thereto. Theannular slot fits over the hub of the pulley of a popular existing typeof internal combustion engine when the beehive-shaped body issuperimposed.

over the hub. A dowel in the annular slot engages the notch in thepulley to prevent relative rotation, By fastening the nut to thecrankshaft, the attaching operation is completed.

BRIEF DESCRIPTION OF THE DRAWINGS FIG. 1 is a side elevation of aninternal combustion engine having the manual starting device of thisinven- 7 DESCRIPTION OF THE PREFERRED EMBODIMENT The beehive-shaped body40, as shown in the drawings, comprises the base 42, the apex 41, theannular slot 43 which opens toward the base 42, the well 44 having abottom which substantially coincides with the base 42 and a circularside 45 which also forms the inner side of the annular slot 43, and thecentral opening 46 in the bottom of the well. Covering the outer side ofthe beehive-shaped body 40 is a spiral groove, consisting of the singlegrooves 52 leading from the notch 51 and leading to the base groove 53which is adjacent to the base 42 of the body and has the double groove54 as the initial portion thereof between a convenient lead-off point 58and the doubled lead-off point 59 which is in radial alignment with thenotch 51.

As shown in FIG. 1, an engine 20, such as is used in a typical lawnmower, has a throttle 21 and a pulley 22 which is coaxially attached toa crankshaft 23 and secured thereto with a nut 26. The pulley 22 has ahub 24 in which is a keyway 27 at the lip thereof. As shown particularlyin FIG. 4, the annular slot 43 fits over the hub 24 of the pulley 22 sothat when the dowel 47 is aligned with the keyway 27, the body 40 isnonrotatably adjacent to the engine 20, the crankshaft 23 being, ofcourse, coaxially inserted into the opening 46. When the nut 26 issecured onto the crankshaft 23, the body 40 is rigidly attached to theengine 20.

A pull rope 56, having a handle 57, is attached at its terminus to thenotch 51 in the body 40 and is wound along the spiral grooves 52 andthen into the base groove 53 for one full turn to the convenientlead-off point 58. Additional power, however, can be obtained by windingan additional portion along the short double-width groove 54 to thedoubled lead-off point 59 so that four full turns of rope are available.

After the pull rope 56 has been pulled, perpendicularly to the axis ofthe crankshaft 23, through two to three turns, firing of the engine bycombustion of the mixture in the cylinders usually begins. At thispoint, the single grooves 52 of the beehive-shaped body of thisinvention rapidly progress inwardly toward the notch 51 at the apex 41.Rotational velocity of the engine, as engine power augmentshand-starting power,

normally increases at this point, and less pulling power is needed.Thereafter, the pull rope simply maintains a diminishing but steadypower input and steadily increasing rotational velocity for the finalone or two turns. As a result, the powerful, high-compression, largerengines of the present day are readily started.

What has been described hereinbefore may be modified by those skilled inthe art, but what is intended to be protected as coming within the scopeof the invention is defined in the following claims.

What is claimed is:

l. A manual starting device for an internal combustion engine attachedto the crankshaft of said engine, comprising a beehive-shaped bodyhaving a spiral groove of sufficient width to accomodate a pull rope,said groove having an initial double width along a portion of its lengthat the base of said body and terminating in a pull notch at the apexthereof within four full turns.

2. The device of claim 1 wherein the diameter of said base is 6.2 inchesand the cumulative circumference, 6, of said spiral groove, as measuredby the length of wound pull rope thereupon, is given in inches per turn,

as c= 20.0 1

3. The device of claim Lwherein said engine has a pulley thereon andsaid body is attached to said crankshaft by superimposing said body overthe hub of said pulley.

4. The device of claim 3 wherein said body has a central well which isopen on the apex end of said body and an annular slot that is open onthe base side of said body,-said well having a base that is flush withsaid base and sides which form the sides of said slot, said base havinga central opening that fits said crankshaft.

5. The device of claim 4 wherein a dowel at the base of said slotprojects toward said engine and mates with a keyway in said hub toprevent said body from rotating independently of said hub.

1. A manual starting device for an internal combustion engine attachedto the crankshaft of said engine, comprising a beehiveshaped body havinga spiral groove of sufficient width to accomodate a pull rope, saidgroove having an initial double width along a portion of its length atthe base of said body and terminating in a pull notch at the apexthereof within four full turns.
 1. A manual starting device for aninternal combustion engine attached to the crankshaft of said engine,comprising a beehive-shaped body having a spiral groove of sufficientwidth to accomodate a pull rope, said groove having an initial doublewidth along a portion of its length at the base of said body andterminating in a pull notch at the apex thereof within four full turns.2. The device of claim 1 wherein the diameter of said base is 6.2 inchesand the cumulative circumference, C, of said spiral groove, as measuredby the length of wound pull rope thereupon, is given in inches per turn,T, as: C 20.0 T0.90
 3. The device of claim 1 wherein said engine has apulley thereon and said body is attached to said crankshaft bysuperimposing said body over the hub of said pulley.
 4. The device ofclaim 3 wherein said body has a central well which is open on the apexend of said body and an annular slot that is open on the base side ofsaid body, said well having a base that is flush with said base andsides which form the sides of said slot, said base having a centralopening that fits said crankshaft.